1. Field of the Invention
The present invention relates to slug removal devices and, more specifically, to a hole saw slug removal device used to automatically eject plugs that have been sawed from material.
2. Description of the Related Art
A hole saw is a type of saw used in drilling circular holes in various materials, such as wood, metal, drywall, etc. The hole saw typically has a cylindrical body, one edge of which is serrated. In addition, the cylindrical body contains openings at both ends that allow for a drill bit to be extended therefrom. The drill bit juts out just beyond the serrated edge and stabilizes the hole saw against the surface of the material. When used with a drill power source, the serrated edge of the hole saw body rotates, creating circular holes in the material.
A substantial problem that is faced in employing the hole saw to drill holes in a surface is that the waste left over, typically called a slug, is difficult to extract from within the body of the hole saw. The user is required to stop after each hole is sawed and manually extract the slug from the hole saw. This manual slug removal technique is time-consuming and takes substantial effort for the user. Thus, a hole saw which allows for quick removal of the slug provides much greater use for the user. Automatic removal of the slug would be preferential to non-automatic slug removal.
The related art endeavors to solve the problem of slug removal by either developing different types of hole saws to eject the slugs or by developing a slug removal device to be connected to the hole saw.
U.S. Pat. No. 3,390,596, issued Jul. 2, 1968 to Trevathan, discloses a cutting head assembly which may be utilized to bore circular holes. The cutting head assembly has a cylindrical body, with a plurality of cutting teeth on one edge of the body. The plurality of cutting teeth appear to preferably consist of inwardly and outwardly extending teeth. A spring is positioned within the body portion, and a spring-actuated disc is inserted within the cylindrical body, the disc being used to decrease distortion in the hole shape. The disc and spring appear to be held within the cylindrical body of the cutting head assembly by the inwardly extending teeth. When attached to a power source, the cutting head assembly is rotatably driven about its axis such that a hole is cut into the surface of the material on which it is placed.
U.S. Pat. No. 4,652,185, issued Mar. 24, 1987 to Malrick, shows a hole saw and slug removing device. The hole saw has a cylindrical body through which a drill bit may pass, one edge o the cylindrical body being serrated such that when the hole saw is used, a circular hole is drilled into a surface. A plug member is positioned within the hole saw using a set of screws inserted through an annular collar and into the plug member. The screws maintain the plug member within the hole saw. It appears that a spring may be positioned within the hole saw between an inner portion of the hole saw and the plug member and become compressed when the hole saw is operated. After the hole has been made, the hole saw operator may extract the slug from within the hole saw by manually pressing down on the annular collar.
U.S. Pat. No. 5,816,752, issued Oct. 6, 1998 to Benjamin, describes a slug removal system. The system includes a knock-out device which ejects slugs after a hole is drilled using a hole saw. The knock-out device has a cylindrical body which is tapered at one end and fits inside the hole saw. A spring is included as part of the slug removal system. As the hole saw is used, the knock-out device is pushed back against the spring. When the hole is completed, the spring decompresses, ejecting the slug from within the hole saw. A set of screws secures the knock-out device to the hole saw at predetermined depths.
Although the related art does address devices for slug removal, what is needed is a simple device, easily constructed, that automatically removes slugs. What is further needed is a device for slug removal that may be attached to hole saws that lack a slug removal device. The device should allow for simple insertion within the body of a hole saw and should not require the addition of attachment means that are situated on the outside of the hole saw body. Further, it is advantageous to have a slug removal device that may be removed and later reattached to a hole saw.
None of the above inventions and patents, taken either singly or in combination, is seen to describe the instant invention as claimed. Thus a hole saw slug removal device solving the aforementioned problems is desired.